Conventional practice for draining a periodontal abscess (i.e., an abscess in the gum or bone adjacent to a tooth) is to make an incision through the gum to the abscess site, insert a drainage tube, commonly either a dam drain or a Penrose drain, and allow the abscess to drain for several days (e.g. three or four days), until the pus has been drained. Only after the abscess has been drained can the dentist treat the site to rid it of infection.
The dam drain is not manufactured as a drain, but rather in the form of square sheets of a pharmaceutically acceptable grade of rubber or latex (e.g. "Natsyn" rubber) which may be cut to desired size and rolled into a tube at the dentist's office and inserted into the patient's mouth at the incision site by the dentist. Actually, the primary purpose of the dental dam is simply to keep the incision open until the abscess has drained, rather than to form a device for fashioning into a drainage tube.
The other widely used device is a Penrose drain. The Penrose drain is a collapsible tube, made of a pharmaceutically acceptable x-ray opaque rubber in various sizes. It is generally flat as packaged and shipped. It may be folded. The Penrose drain is manufactured primarily for medical and veterinary use, rather than dental use, although it is available in small sizes suitable for dental use. The Penrose drain may be (and frequently is) cut to desired size.
One difficulty with both the dental dam and the Penrose drain is that neither is prone to stay in place for the entire time (about three or four days) required for dental drainage. One reason for this is that the dam and the Penrose drain can be sutured to the gum only with great difficulty. In addition, the drain fashioned from a dental dam may not hold its shape over the entire time required.
Although both the dental dam and the Penrose drain leave something to be desired, they nevertheless represent the best drainage aids available and are the most widely used drainage aids. What is needed is a drainage aid which will stay in place for the entire length of time required for drainage and will effectively serve as a conduit to drain pus away from the abscess.